This will be an automated manual, referred to as an EGS or EGC. While a driver would not be able to damage the clutch by slipping it (the most common reason for clutch failure), if she habitually sat on the brakes at traffic lights, leaving the transmission in Drive, and the engine did not automatically switch off, then that could have the effect of wearing the clutch. I think there's room for negotiation and goodwill here under the extended warranty, so that's the way to tackle it.